罗1区长8层超低渗储层堵塞机理研究及对策

Plugging mechanism and countermeasures of ultralow permeability Chang8 reservoirs in Luol area

罗1区长8层油藏天然能量不足，储层致密，需要注水开发，但注水后出现注水压力快速升高、注水困难的现象，通过对该区储层特征、敏感性、地层水化学特征和注入水性质进行分析，明确了注入低矿化度清水是造成储层水敏和速敏伤害，导致注水压力持续上升、注水量逐渐减小的主要外因，胶结密实、孔隙度小、渗透率低，是造成注水压力高、注水困难的内在因素。可以采取同层采出水处理后回注并加入粘土稳定剂减少地层结垢，对于已存在地层堵塞的井可以采取酸化措施解堵。

The natural energy of Chang8 reservoirs in Luol area is insufficient. The reservoirs are tight and need watertlooding. It appeals phenomena of injection pressure increasing rapidly after waterflooding and being difficult to waterflood. Through analysis of the reservoir characteristics, sensitivity, chemical features of the formation water, and injection water properties, it is clear and definite that the injection of low salinity water is mainly the external cause of the reservoir water sensitivity and velocity sensitivity damages, leading to continuous rise of water injection pressure, and gradual decreasing of waterflooding volume. The dense cement, small porosity, and low permeability are the inner factors of high waterflooding pressure and injection difficulty. You can take the same layer produced water treatment then reinjection, and adding clay stabilizer to reduce formation scaling. For the formation-plugged wells we can take acidification measures for deplugging.